From 6543884366b4842d6847c435e85f7c49d189974c Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Thu, 26 Sep 2019 22:22:11 -0300
Subject: [PATCH] analysis: add check of composite types (structs and enums)

 - analysis: add bool check for loop condition exprs
---
 examples/hello.ry |  7 +++-
 src/types.zig     | 85 +++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 81 insertions(+), 11 deletions(-)

diff --git a/examples/hello.ry b/examples/hello.ry
index 886e348..f338ce4 100644
--- a/examples/hello.ry
+++ b/examples/hello.ry
@@ -17,8 +17,13 @@ enum B {
     c
 }
 
+enum C {
+    blah
+    bluh
+}
+
 fn test_function() B {
-    return B.a;
+    return B.bluh;
 }
 
 fn multwo(num: i32, double_flag: bool) i32 {
diff --git a/src/types.zig b/src/types.zig
index d1d7a3b..50ab2bb 100644
--- a/src/types.zig
+++ b/src/types.zig
@@ -88,14 +88,75 @@ pub const TypeSolver = struct {
         }
     }
 
-    pub fn expectSymUnType(self: *@This(), symbol_type: comp.SymbolUnderlyingType, wanted_type: comp.SymbolUnderlyingTypeEnum) !void {
-        var actual_type = comp.SymbolUnderlyingTypeEnum(symbol_type);
-        if (actual_type != wanted_type) {
-            std.debug.warn("Expected {}, got {}\n", wanted_type, actual_type);
+    /// Check if the given symbol type matches a given category.
+    /// Does not validate equality of Structs and Enums.
+    pub fn expectSymUnTypeEnum(
+        self: *@This(),
+        symbol_type: comp.SymbolUnderlyingType,
+        wanted_type_enum: comp.SymbolUnderlyingTypeEnum,
+    ) !void {
+        var actual_enum = comp.SymbolUnderlyingTypeEnum(symbol_type);
+        if (actual_enum != wanted_type_enum) {
+            std.debug.warn("Expected {}, got {}\n", wanted_type_enum, actual_enum);
             return CompileError.TypeError;
         }
     }
 
+    fn compositeIdentifierEqual(
+        self: *@This(),
+        typ_enum: comp.SymbolUnderlyingTypeEnum,
+        sym_ident: []const u8,
+        expected_ident: []const u8,
+    ) !void {
+        if (!std.mem.eql(u8, sym_ident, expected_ident)) {
+            self.doError(
+                "Expected {} {}, got {}",
+                @tagName(typ_enum),
+                expected_ident,
+                sym_ident,
+            );
+
+            return CompileError.TypeError;
+        }
+    }
+
+    /// Check if the given type matches the given expected type.
+    /// This does proper validation of the types if they're structs or enums.
+    pub fn expectSymUnTypeEqual(
+        self: *@This(),
+        symbol_type: comp.SymbolUnderlyingType,
+        expected_type: comp.SymbolUnderlyingType,
+    ) !void {
+        const symbol_enum = comp.SymbolUnderlyingTypeEnum(symbol_type);
+        const expected_enum = comp.SymbolUnderlyingTypeEnum(expected_type);
+
+        if (symbol_enum != expected_enum) {
+            std.debug.warn("Expected {}, got {}\n", expected_enum, symbol_enum);
+            return CompileError.TypeError;
+        }
+
+        // for most cases, this is already enough, however, for
+        // composite/abstraction types (structs & enums) we must check
+        // if they're actually equal types inside
+
+        switch (expected_type) {
+            .Struct => |expected_identifier| try self.compositeIdentifierEqual(
+                .Struct,
+                symbol_type.Struct,
+                expected_identifier,
+            ),
+
+            .Enum => |expected_identifier| try self.compositeIdentifierEqual(
+                .Enum,
+                symbol_type.Enum,
+                expected_identifier,
+            ),
+
+            // for everything else, an enum equality test is enough
+            else => {},
+        }
+    }
+
     // TODO make return type optional and so, skip exprs that
     // fail to be fully resolved, instead of returning CompileError
     pub fn resolveExprType(
@@ -193,7 +254,10 @@ pub const TypeSolver = struct {
                     // TODO we need to fetch the given
                     // struct field (on get.name) type and return it
                     .Struct => @panic("TODO analysis of struct"),
+
+                    // TODO check if get.name exists in enum
                     .Enum => return global_typ,
+
                     else => {
                         std.debug.warn(
                             "Expected Struct/Enum as get target, got {}\n",
@@ -238,13 +302,13 @@ pub const TypeSolver = struct {
             // pull a hack with err contexts, lol)
             .Return => |ret| {
                 var ret_stmt_type = try self.resolveExprType(ctx, ret.value);
-                try self.expectSymUnType(ret_stmt_type, ctx.cur_function.?.return_type);
+                try self.expectSymUnTypeEqual(ret_stmt_type, ctx.cur_function.?.return_type);
             },
 
             // If create two scopes for each branch of the if
             .If => |ifstmt| {
                 var cond_type = try self.resolveExprType(ctx, ifstmt.condition);
-                try self.expectSymUnType(cond_type, .Bool);
+                try self.expectSymUnTypeEnum(cond_type, .Bool);
 
                 try ctx.bumpScope("if_then");
 
@@ -267,9 +331,10 @@ pub const TypeSolver = struct {
             // Loop (creates 1 scope) asserts that the expression
             // type is a bool
             .Loop => |loop| {
-                if (loop.condition) |cond|
-                // TODO assert condition's type is bool
-                    _ = try self.resolveExprType(ctx, cond);
+                if (loop.condition) |cond| {
+                    var expr = try self.resolveExprType(ctx, cond);
+                    try self.expectSymUnTypeEnum(expr, .Bool);
+                }
 
                 // TODO bump-dump scope
                 for (loop.then_branch.toSlice()) |then_stmt| {
@@ -303,7 +368,7 @@ pub const TypeSolver = struct {
                 self.setErrContext("function {}", name);
                 var ret_type = self.resolveGlobalType(ctx, decl.return_type.lexeme);
 
-                std.debug.warn("start analysis of fn {} ret_type: {}\n", decl.func_name.lexeme, ret_type);
+                std.debug.warn("start analysis of fn {}, ret type: {}\n", decl.func_name.lexeme, ret_type);
 
                 var parameters = comp.TypeList.init(self.allocator);
                 for (decl.params.toSlice()) |param| {